ISO 3951-1 : 2013

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols
5 Acceptance quality limit (AQL)
6 Switching rules for normal, tightened, and
   reduced inspection
7 Relation to ISO 2859-1
8 Consumer protection
9 Allowing for measurement uncertainty
10 Planning
11 Choice between variables and attributes
12 Choice between the s-method and sigma-method
13 Choice of inspection level and AQL
14 Choice of sampling scheme
15 Preliminary operations
16 Standard procedures for the s-method
17 Standard procedures for the sigma-method
18 Procedure during continuing inspection
19 Normality and outliers
20 Records
21 Operation of switching rules
22 Discontinuation and resumption of inspection
23 Switching between the s-method and sigma-method
24 Charts B to R - Operating characteristic curves
   and tabulated values for single sampling plans,
   normal inspection: s-method
25 Charts s-D to s-R - Acceptance curves for combined
   control of double specification limits: s-method
Annex A (normative) - Table for determining the sample
        size code letter
Annex B (normative) - Form k for single sampling plans:
        s-method
Annex C (normative) - Form k for single sampling plans:
        sigma-method
Annex D (normative) - Values of f[s] for maximum sample
        standard deviation (MSSD)
Annex E (normative) - Values of f[sigma] for maximum
        process standard deviation (MPSD)
Annex F (normative) - Estimating the process fraction
        nonconforming for sample size 3: s-method
Annex G (normative) - Single sampling plans of Form p*
Annex H (normative) - Values of c[U] for upper control limit
        on the sample standard deviation
Annex I (normative) - Supplementary acceptability constants
        for qualifying towards reduced inspection
Annex J (normative) - Procedures for obtaining s and sigma
Annex K (informative) - Consumer's risk qualities
Annex L (informative) - Producer's risks
Annex M (informative) - Operating characteristics for the
        sigma-method
Annex N (informative) - Estimating the process fraction
        nonconforming for sample sizes 3 and 4: s-method
Annex O (normative) - Accommodating measurement variability
Bibliography

This part ofISO3951is primarily designed for use under the following conditions:a)where the inspection procedure is to be applied to a continuing series of lots of discrete products all supplied by one producer using one production process;b)where only a single quality characteristic,x, of these products is taken into consideration, which must be measurable on a continuous scale;c)where production is stable (under statistical control) and the quality characteristic,x, is distributed according to a normal distribution or a close approximation to the normal distribution;d)where a contract or standard defines a lower specification limit,L, an upper specification limit,U, or both; an item is qualified as conforming if and only if its measured quality characteristic,x,satisfies the appropriate one of the following inequalities:1)x≥L(i.e. the lower specification limit is not violated);2)x≤U(i.e. the upper specification limit is not violated);3)x≥Landx≤U(i.e. neither the lower nor the upper specification limit is violated).